Small-caliber ammunition for breaching barriers

ABSTRACT

A small-caliber ammunition is disclosed. The small-caliber ammunition includes a casing and a frangible projectile located within the casing. The frangible projectile includes a metal inert capsule and a reactive material (RM) pellet embedded within the metal inert capsule. The top surface of the RM pellet flushes with the top surface of the metal inert capsule. The casing contains a smokeless propellant and a primer for igniting the smokeless propellant.

TECHNICAL FIELD

The present invention relates to ammunitions in general, and in particular to small-caliber ammunitions for allowing law enforcement and military personnel to perform forced-entry via explosive breaching.

BACKGROUND

In certain tactical situations, law enforcement and military personnel are called upon to gain entry into a barricaded structure such as a barricaded door. It is a standard practice for the barricaded door to be approached by a squad of four to five personnel stacked in a line. The first (front) person of the squad is charged with the task of breaching the door. After the door has been breached, the remaining members of the squad can rush through the door.

A battering ram is commonly used to breach a door. Most battering rams are basically heavy pipes, which weigh approximately forty pounds, with handles. A battering ram can be swung into a door in the vicinity of a latch to break open the door. Typically both hands are needed to breach a door in this manner. As a result, the operator who is charged with breaching the door is completely exposed when the door bursts open.

Consequently, it would be desirable to provide an improved apparatus for breaching doors.

SUMMARY OF THE INVENTION

In accordance with a preferred embodiment of the present invention, a small-caliber ammunition includes a casing and a frangible projectile located within the casing. The frangible projectile includes a metal inert capsule and a reactive material (RM) pellet embedded within the metal inert capsule. The top surface of the RM pellet flushes with the top surface of the metal inert capsule. The casing contains a smokeless propellant and a primer for igniting the smokeless propellant.

All features and advantages of the present invention will become apparent in the following detailed written description.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention itself, as well as a preferred mode of use, further objects, and advantages thereof, will best be understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawings, wherein:

FIG. 1 is an isometric view of a small-caliber ammunition to be used for breaching barriers, in accordance with one embodiment;

FIG. 2 is a cross-sectional view of the ammunition from FIG. 1 , in accordance with one embodiment; and

FIG. 3 is a cross-sectional view of a frangible projectile within the ammunition from FIG. 1 , in accordance with one embodiment.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

A tactical door-breaching operation can be performed by using a handgun with its muzzle in contact with (or as close as possible to) a door. A special small-caliber ammunition is designed for this purpose. One or more shots can be fired into the door jamb to break open the door.

Referring now to the drawings and in particular to FIG. 1 , there is illustrated an isometric view of a small-caliber ammunition to be used for breaching barriers such as doors, in accordance with one embodiment. As shown, an ammunition 10 includes a casing 11 carrying a frangible projectile 12. Frangible projectile 12 can be of a relatively small caliber, such as a 9 mm projectile round, capable of being fired from a pistol or rifle. The total launch mass of frangible projectile 12 ranges from 0.5 g to 10.0 g preferably, but it can be as large as 100 g.

With reference now to FIG. 2 , there is illustrated a cross-sectional view of ammunition 10, in accordance with one embodiment. As shown, frangible projectile 12 is carried by casing 11 that contains a smokeless propellant 13 and a percussion primer 14. Frangible projectile 12 can be propelled away from casing 11 by smokeless propellant 13 initiated by percussion primer 14. Smokeless propellant 13 is designed to achieve maximum velocity while limiting the chamber pressure of casing 11 to 40,000 psi or less for pistol calibers, but it can be extended to 65,000 psi for rifle calibers. Examples of smokeless propellant 13 include Hodgdon Tightgroup and Hodgdon 110, although other propellants can also be employed.

Referring now to FIG. 3 , there is illustrated a detailed cross-sectional view of frangible projectile 12, in accordance with one embodiment. As shown, frangible projectile 12 includes a reactive material (RM) pellet 31 embedded within an inert capsule 32. A top surface 36 of RM pellet 31 is slightly recessed from a top surface 35 of inert capsule 32 in order to receive a potting compound 37. Potting compound 37 acts as a shock buffer to control the timing of the initiation of the reactive materials in RM pellet 31 to allow the tuning of energy release into a target.

Preferably, inert capsule 32 is made of metal, such as brass or copper, in order to survive through a rifled barrel of a firearm. The shape of inert capsule 32 may be formed by pressing, casting, extruding, or injection molding. For the present embodiment, the base of inert capsule 32 is substantially cylindrical in order to match with the circumference of casing 11, while it is slightly tapered towards top surface 35. The ogive shape of inert capsule 32 allows functions in semi-automatic actions based on the way it engages with the feed ramp of a firearm. Top surfaces 35, 36 are substantially flat.

RM pellet 31 is substantially cylindrical in shape having a pointed tip 33 opposite top surface 36. The center of RM pellet 31 is concentric with the center of inert capsule 32. The height of RM pellet 31 is in the range of, for example, 0.250 in to 0.500 in. The diameter of RM pellet 31 is in the range of, for example, 0.125 in to 0.170 in. The mass of RM pellet 31 can be altered by varying the length and/or the diameter of RM pellet 31.

RM pellet 31 can be formed by drilling top surface 35 of inert capsule 32 to provide a cavity within inert capsule 32, and reactive materials are then pressed directly into the cavity within inert capsule 32. The cavity can be formed within inert capsule 32 by using, for example, a twist drill that has a 118 ° included angle. Potting compound 37 is subsequently utilized to hermetically seal the reactive materials of RM pellet 31 within the cavity of inert capsule 32 to prevent any degradation of reactive materials due to atmospheric exposure.

The reactive materials within RM pellet 31 are made up of energetic materials that include two or more solid-state reactants that together form a thermochemical mixture. For example, the reactive materials may include metal-metal and/or metal-metal oxide mixtures with and without binders included. Reactive materials have higher predicted energy per unit volume than conventional energetics and can provide alternate kill mechanisms besides those from conventional energetics.

In order to reduce collateral damages behind a target, RM pellet 31 is made from metal powders and binders. For example, RM pellet 31 can be made of various reactive materials or from a mixture of reactive materials, including binders, fuels and oxidizers. Binding agent is required due to the high forces during launch. The binder in RM pellet 31 may include a small percentage of PTFE, wax, lacquer, epoxy, or other polymers. The binder is used in the reactive material to provide improved processability, safety, or performance. If the reactive material is to be pressed, the reactive material may include at least one fuel and at least one oxidizer, or at least two fuels. The reactive material may be an intermetallic composition or a thermitic composition, or other pyrotechnic composition. The fuel may include aluminum, iron, zirconium, magnesium, zinc, titanium, lithium, boron, and/or alloys. The oxidizer may include potassium perchlorate, potassium chlorate, potassium nitrate, ammonium perchlorate, ammonium chlorate, ammonium nitrate, lithium perchlorate, lithium chlorate, lithium nitrate, molybdenum oxide, copper oxide, tungsten oxide, iron oxide, bismuth oxide, polytetrafluoroethylene (PTFE), perfluoropolyether (PFPE) and a combination thereof.

Additional adjustments can be made on RM pellet 31 in order to improve the performance of RM pellet 31. For example, the mass and type of RM pellet 31 can be tuned up or down to manage target damage and operator safety. The reactive material within RM pellet 31 can be pressed or cast to improve manufacturing costs.

A critical minimum wall thickness is required for inert capsule 32 to survive through a rifled barrel of a firearm. Preferably, the ratio of RM pellet 31's diameter to frangible projectile 12's diameter is in the range of 1:3.5 to 1:2.0.

The shock from RM pellet 31 is initiated upon impact with a target. Basically, chemical and kinetic energies from RM pellet 31 are delivered to the target. The timing of the release of the chemical energy can be tuned via reactive materials to frangible projectile 12 morphology in order to achieve a desired effect. This is accomplished based on the position of RM pellet 31 within frangible projectile 12, which determines when impact shock reaches RM pellet 31. This effect allows timing adjustment of initial impact with a target.

As has been described, the present invention provides an improved ammunition for breaching barriers made of metal, wood or masonry.

While the invention has been particularly shown and described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the invention. 

What is claimed is:
 1. An ammunition comprising: a casing; a frangible projectile, located within said casing, includes a metal inert capsule; a reactive material (RM) pellet embedded within said metal inert capsule, wherein a top surface of said RM pellet is recessed from a top surface of said metal inert capsule; and a smokeless propellant and a primer, contained with said casing, for igniting said propellant.
 2. The ammunition of claim 1, wherein said top surface of said RM pellet is hermetically sealed by a potting compound.
 3. The ammunition of claim 1, wherein said inert capsule has a cylindrical base and a tapered top.
 4. The ammunition of claim 1, wherein said inert capsule includes a nose and an annulus.
 5. The ammunition of claim 1, wherein said RM pellet is concentric with said inert capsule.
 6. The ammunition of claim 1, wherein said RM pellet is a homogeneous structure within said inert capsule.
 7. The ammunition of claim 1, wherein said RM pellet is made of a plurality of reactive materials.
 8. The ammunition of claim 7, wherein said reactive materials includes at least one binder, at least one fuel and at least one oxidizer.
 9. The ammunition of claim 8, wherein said fuel includes at least one of aluminum, iron, zirconium, magnesium, zinc, titanium, lithium, boron, and alloys.
 10. The ammunition of claim 9, wherein said oxidizer includes at least one of potassium perchlorate, potassium chlorate, potassium nitrate, ammonium perchlorate, ammonium chlorate, ammonium nitrate, lithium perchlorate, lithium chlorate, lithium nitrate, molybdenum oxide, copper oxide, tungsten oxide, iron oxide, bismuth oxide, polytetrafluoroethylene (PTFE), perfluoropolyether (PFPE) and combinations thereof.
 11. The ammunition of claim 1, wherein said inert capsule is cast into a mold, and said RM pellet is cast into a cavity within said inert capsule.
 12. The ammunition of claim 1, wherein said inert capsule is pressed into a mold, and said RM pellet is pressed into a cavity within said inert capsule.
 13. The ammunition of claim 1, wherein the position of said RM pellet within said inert capsule determines when an impact shock reaches said RM pellet.
 14. The ammunition of claim 1, wherein said smokeless propellant includes Hodgdon Tightgroup or Hodgdon
 110. 